Toyota Prius
The Toyota Prius ( ; plural: Prii ) is a full hybrid electric mid-size hatchback, formerly a compact sedan developed and manufactured by Toyota. The EPA and California Air Resources Board (CARB) rate the Prius as among the cleanest vehicles sold in the United States based on smog-forming emissions. The Prius first went on sale in Japan in 1997, and was available at all four Toyota Japan dealerships, making it the first mass-produced hybrid vehicle. It was subsequently introduced worldwide in 2000. The Prius is sold in almost 80 countries and regions, with its largest markets being those of Japan and the United States. Global cumulative Prius sales reached the milestone 1 million vehicle mark in May 2008, 2 million in September 2010, and passed the 3 million mark in June 2013. Cumulative sales of 1 million Prii were achieved in the U.S. by early April 2011, and Japan reached the 1 million mark in August 2011. In 2011, Toyota expanded the Prius family to include the Prius v, an extended hatchback wagon, and the Prius c, a subcompact hatchback. The production version of the Prius plug-in hybrid was released in 2012. The Prius family reached global cumulative sales of 3.8 million units by June 2013, representing 71.7% of Toyota hybrid sales of 5.3 million Lexus and Toyota units sold worldwide since 1997. Etymology and terminology Prius is a Latin word meaning "before". According to Toyota, the name was chosen because the Prius was launched before environmental awareness became a mainstream social issue. In February 2011, Toyota asked the public to decide on what the most proper plural form of Prius should be, with choices including Prien, Prii, Prium, Prius, or Priuses. The company said it would "use the most popular choice in its advertising" and on February 20 announced that "Prii" was the most popular choice, and the new official plural designation. In Latin prius is the neuter singular of the comparative form (prior, prior, prius) of an adjective with only comparative and superlative (the superlative being primus, prima, primum), consequently, like all 3rd declension words, the plural in Latin was priora (cf. Latin declension) which was used by the Lada Priora in 2007. Beginning in September 2011, Toyota USA began using the following names to differentiate the original Prius from some newer members of the Prius family: the standard Prius became the Prius Liftback, the Prius v (known as the Prius α in Japan, and Prius + in Europe), the Prius Plug-in Hybrid, and the Prius c (called Toyota Aqua in Japan). First generation (XW10; 1997–2003) In 1995, Toyota debuted a hybrid concept car at the Tokyo Motor Show, with testing following a year later. The first Prius, model NHW10, went on sale on December 10, 1997. It was available only in Japan, though it has been imported privately to at least the United Kingdom, Australia, and New Zealand. The first generation Prius, at its launch, became the world's first mass-produced gasoline-electric hybrid car. At its introduction in 1997, it won the Car of the Year Japan Award, and in 1998, it won the Automotive Researchers' and Journalists' Conference Car of the Year award in Japan. The NHW10 Prius styling originated from California designers, who were selected over competing designs from other Toyota design studios. In the United States, the NHW11 was the first Prius to be sold. The Prius was marketed between the smaller Corolla and the larger Camry. The published retail price of the car was . The NHW11 Prius became more powerful partly to satisfy the higher speeds and longer distances that Americans drive. Air conditioning and electric power steering were standard equipment. The vehicle was the second mass-produced hybrid on the American market, after the two-seat Honda Insight. While the larger Prius could seat five, its battery pack restricted cargo space. The US EPA (CARB) classified the car with an air pollution score of 3 out of 10 as an Ultra Low Emission Vehicle (ULEV). Prius owners were eligible for up to a federal tax deduction from their gross income. In contrast with the NW10, Toyota executives stated that the company broke even financially on sales of the NHW11 Prius. European sales began in September 2000. The official launch of the Prius in Australia occurred at the October 2001 Sydney Motor Show, although sales were slow until the NHW20 (XW20) model arrived. Toyota sold about 42,000 first generation Prii. Second generation (XW20; 2003–2009) In 2003 (for the 2004 US model year) the Prius was completely redesigned as a mid-size liftback, sized between the Corolla and the Camry, with redistributed mechanical and interior space significantly increasing rear-seat legroom and luggage room. The new Prius is even more environmentally friendly than the previous model (according to the EPA), and is longer than the previous version. Its more aerodynamic Kammback body balances length and wind resistance, resulting in a . The development effort, led by chief engineer Shigeyuki Hori, led to 530 patents for the vehicle. The Prius uses an all-electric A/C compressor for cooling, an industry first. Combined with a smaller and lighter NiMH battery, the XW20 is more powerful and more efficient than the XW10. In the U.S., the battery pack of 2004 and later models is warranted for or 10 years in states that have adopted the stricter California emissions control standards, and or 8 years elsewhere. The warranty for hybrid components is or 8 years. It is classified as a SULEV (Super Ultra Low Emissions Vehicle) and is certified by California Air Resources Board as an "Advanced Technology Partial Zero Emission Vehicle" (AT-PZEV). From 2005 to 2009, the second generation Prius had been built by FAW-Toyota in the city of Changchun for the Chinese market. It was reported that a total of 2,152 Prii were sold in 2006 and 414 in 2007. The relatively low sales was blamed on high price, about higher than the equivalent in Japan or the U.S., caused by high duties on imported parts. In early March 2008, Toyota cut the price of Prius by up to eight percent or to ( ). It was thought that the sales dropped as a result of both a lack of acceptance and increased competition. The Honda Civic Hybrid was exported to China from 2007. Toyota sold about 1,192,000 second generation Prii worldwide. Safety U.S. National Highway Traffic Safety Administration (NHTSA) crash testing of the 2004 US model year Prius yielded a five-star driver and four-star passenger rating in the frontal-collision test (out of five stars). Side crash results were four out of five stars for both front and rear seats. The car scored four out of five stars in rollover testing. U.S. Insurance Institute for Highway Safety crash tests scored the Prius Good overall in frontal collisions and Good overall in side-impact collisions in models equipped with side airbags. A Poor score was given to models without side airbags. Side curtain and torso airbags became standard on 2007 American models. Third generation (XW30; 2009–present) Toyota debuted the new Prius (2010 US model year) at the January 2009 North American International Auto Show, and sales began in Japan on May 18, 2009. Toyota cut the price of the Prius from to to better compete with the Honda Insight, leading some to wonder whether increased sales of the Prius might come at the expense of sales of other vehicles with higher margins. Competition from lower priced hybrids, such as the Honda Insight, also made it difficult for Toyota to capitalize on the Prius's success. In addition, in United Kingdom, 60 Toyota Prius vehicles have been ordered and in Singapore, over 20 Toyota Prius vehicles have been ordered. Its new body design is more aerodynamic, with a reduced . This figure is disputed by General Motors which found the value for the model with 17" wheels to be around 0.30 based on tests in GM, Ford, and Chrysler wind tunnels. An underbody rear fin helps stabilize the vehicle at higher speeds. The estimated fuel-efficiency rating, using the U.S. EPA combined cycle, is . The Prius was the most efficient car powered by liquid fuel available in the U.S. in 2009, based on the official rating. Only the first-generation Honda Insight (2000–2006) equipped with a manual transmission attained a lower fuel consumption rate. The official UK fuel efficiency data for the Prius T3 is Urban , Extra Urban , Combined . The 1.8-liter gasoline engine (previously 1.5 liters) generates , and with the added power of the electric motor generates a total of (previously ). The larger engine displacement allows for increased torque, reducing engine speeds (RPM), which improves fuel economy at highway speeds. Thanks to its electric water pump, the Prius engine is the first consumer automotive production engine that requires no accessory belts, which also further improves its fuel economy. The electric motors and other components of the hybrid powertrain are also smaller and more efficient than the industry average. Toyota estimates the new inverter, motor and transaxle are 20 percent lighter. In constructing the Prius, Toyota used a new range of plant-derived ecological bioplastics, made out of cellulose derived from wood or grass instead of petroleum. The two principal crops used are kenaf and ramie. Kenaf is a member of the hibiscus family, a relative to cotton and okra; ramie, commonly known as China grass, is a member of the nettle family and one of the strongest natural fibres, with a density and absorbency comparable to flax. Toyota says this is a particularly timely breakthrough for plant-based eco-plastics because 2009 is the United Nations’ International Year of Natural Fibres, which spotlights kenaf and ramie among others. On February 12, 2014, Toyota UK announced a recall of the Prius, citing a software error which could cause the car to stop suddenly. Safety The IIHS rated the 2010 Prius as Good except for side-impact "structure/safety cage", which was rated Acceptable. In EuroNCAP testing, the Prius was given an overall rating of five out of five stars 2011 facelift In mid-2011 (for the 2012 model year), the third-generation Prius Liftback received modest style and equipment changes. The exterior changes include updated headlamps, revised tail lamps, plus a distinctive front fascia and bumper, and the deletion of the "Super White" color option in the United States. Prospective American Prius buyers wanting a white exterior must either choose the "Blizzard Pearl" color (a metallic off-white) for an additional $220, or choose another make or model. The Prius can be equipped with an updated infotainment system featuring the optional Toyota Entune suite of connectivity features. Other updates include a 6.1-inch touch-screen, an AM/FM CD player unit, a USB port for iPod connectivity, an auxiliary input jack, a Bluetooth hands-free phone capability and streaming audio. The Prius also includes an optional solar panel on the roof of the car, solely to power a ventilation fan while the car is parked, to keep the interior cooler in sunny conditions. For the U.S. market only the Prius Two, Three, Four and Five were offered. The premium Prius Five model's Advanced Technology Package includes the Premium HDD Navigation System, plus the Head-up Display, Dynamic Radar Cruise Control, Pre-Collision System and Lane Keep Assist. The Pre-Collision System retracts the front seatbelts and applies the brakes in certain conditions when it determines that a crash is unavoidable. Lane Keep Assist can help the driver stay within the lane. The U.S. 2012 model year includes Toyota's Vehicle Proximity Notification System (VPNS), which is designed to alert pedestrians, the blind, and others of the vehicle's presence due to significant noise reduction typical of a hybrid vehicle traveling at low speeds in all-electric mode. Prius family Prius plug-in hybrid The Prius Plug-in Hybrid (ZVW35) is based on the conventional third generation (ZVW30) with a 4.4-kWh lithium-ion battery that allows an all-electric range of . A global demonstration program involving 600 pre-production test cars began in late 2009 and took place in Japan, Europe, Canada, China, Australia, New Zealand and the United States. The production version was unveiled at the September 2011 Frankfurt Motor Show. Deliveries began in Japan in late January 2012, followed by a limited roll-out in the U.S. in late February. Deliveries began in Europe in June 2012 and in the UK in August 2012. During its first year in the market, global sales reached 27,181 Prius PHVs, making the Prius PHV the second top selling plug-in electric car in 2012 after the Chevrolet Volt. , over 35,000 units have been sold worldwide. Prius v At the January 2011 North American International Auto Show, Toyota revealed the 2012 model year [[Toyota Prius v|Prius v'']], an extended hatchback wagon, which is derived from the third-generation Prius and features over 50 percent more interior cargo space than the original Prius design. In May 2011 Toyota introduced the Prius α (alpha) in Japan, which is available in a five-seat, two-row model and a seven-seat, three-row model, the latter’s third row enabled by a space-saving lithium-ion drive battery in the center console. The five-seat model uses a NiMH battery pack. The Alpha is the basis for the five-seat Prius ''v launched in North America in October 2011 with a nickel-metal hydride battery pack similar to the 2010 model year Prius, and with two rows of seats to accommodate five passengers. The European and Japanese versions are offered with a lithium-ion battery, with three rows of seats with accommodations for seven passengers. The European version, named Prius+ (plus), began deliveries in June 2012. About 322,000 Prius α/v/+ have been sold worldwide by June 2013. Prius c Toyota unveiled the Prius c concept at the January 2011 North American International Auto Show. The Prius c has a lower list price and is smaller than the current Prius hatchback. The production version was unveiled at the 2011 Tokyo Motor Show as the Toyota Aqua, and was launched in Japan in December 2011. The Prius c was released in the US and Canada in March 2012, and in April 2012 in Australia and New Zealand. The Prius c is not available in Europe, where instead, Toyota is selling the Toyota Yaris Hybrid since June 2012. The Prius c and the Yaris Hybrid share the same powertrain. The Aqua ranked as the second best selling car in Japan in 2012 after the Prius brand, as Toyota reports together sales of the conventional Prius and the Prius α. When sales of these two Prius models are broken down, the Toyota Aqua ranks as the top selling model in Japan, including kei cars, with the Aqua leading monthly sales since February through December 2012. The Aqua is considered the most successful nameplate launch in Japan in the last 20 years. Since its release, more than 500,000 units have been sold worldwide through August 2013, and sales are led by Japan with 448,703 Aquas, followed by the U.S. with 65,583 Prii c. The Aqua was the top selling new car in Japan in 2013, including kei car sales. Fourth generation In August 2013, Toyota Managing Officer Satoshi Ogiso, who was chief engineer for the Prius line, announced some of the improvements and key features of the next generation Prius, expected to be introduced as early as 2015. The next-generation Prius is being designed to deliver significantly improved fuel economy in a more compact package that is lighter in weight and lower in cost. These objectives are being achieved through the development of a new generation of powertrains with significant advances in battery, electric motor and gasoline engine technologies. The next Prius will feature improved batteries with higher energy density; smaller electric motors, with higher power density than the current Prius motors; and the gasoline engine will feature a thermal efficiency greater than 40% (in the current Prius is 38.5%). The Prius fuel economy has improved on average by about 10% each generation, and Toyota has set the challenge to continue to improve at this rate. The next Prius will feature the Toyota New Global Architecture (TNGA), which provides a lower center of gravity and increased structural rigidity. These features, along with other improvements will allow for gains in ride-and-handling, agility and aerodynamics. The improved aerodynamics will contribute to an all-new exterior design, which includes a roomier interior. Ogiso also explained that the next-generation Prius plug-in hybrid vehicle is being developed in parallel with the standard Prius model. Toyota is developing a new wireless or inductive charging system that produces resonance between an on-floor coil and an onboard coil to transmit power to the battery. The company plans to begin testing of the wireless battery charging system in Japan, the U.S. and Europe in 2014 for a future plug-in Prius. Toyota is also considering requests from Prius PHV owners for additional all-electric range. In December, 2013, Consumer Reports named the Prius as the "Best Value", for the second year in a row. Design and technology The Toyota Prius is a power-split or series-parallel (full) hybrid, where it is sometimes known as a combined hybrid, a vehicle that can be propelled by gasoline or electric power or both. Wind resistance is reduced by a drag coefficient of Cd=0.25 (0.29 for 2000 model) with a Kammback design to reduce air resistance. Lower rolling resistance tires are used to reduce road friction. An electric water pump eliminates serpentine belts. In the US and Canada, a vacuum flask is used to store hot coolant when the vehicle is powered off for reuse so as to reduce warm-up time. The Prius engine makes use of the Atkinson cycle. When the vehicle is turned on with the "Power" button, it is ready to drive immediately with the electric motor. In the second generation Prius, electric pumps warm the engine by pumping previously saved hot engine coolant from a coolant thermos before the internal combustion engine is started. The delay between powering the car on and starting the internal combustion engine is approximately seven seconds. The third generation Prius does not have a coolant thermos. Instead, the engine is heated by recapturing exhaust heat. A button labelled "EV" maintains Electric Vehicle mode after being powered on and under most low-load conditions at less than 25 mph (40 km/h). This permits driving with low noise and no fuel consumption for journeys under 1 mile (1.6 km). The car automatically reverts to normal mode if the battery becomes exhausted. Prior to the 2010 model, the North American model do not have an "EV" button, although the EV mode is supported internally by the Prius Hybrid Vehicle management computer. Batteries There are two principal battery packs, the High Voltage (HV) battery, also known as the traction battery, and a 12 volt battery known as the Low Voltage (LV) battery. The traction battery of the first generation Prius update (2000 onwards) was a sealed 38-module nickel metal hydride (NiMH) battery pack providing 273.6 volt, 6.5 Ah capacity and weighing 53.3 kg (118 lb) and is supplied by Japan's Panasonic EV Energy Co. They are normally charged between 40–60% of maximum capacity to prolong battery life as well as allow headroom for regenerative braking. Each battery pack uses 10–15 kg (22–33 lb) of lanthanum, and each Prius electric motor contains 1 kg (2 lb) of neodymium; production of the car is described as "the biggest user of rare earths of any object in the world." The LV battery is essential to starting the car and providing initial power to the computer. The Second Generation Prius contains a 1.310 kWh battery, composed of 28 modules. Each battery module is made of 6 individual 1.2 V 6.5 Ah Prismatic NiMH cells in series forming a 7.2 V 6.5 Ah module with 46 Wh/kg energy density and 1.3 kW/kg output power density. Each module contains an integrated charge controller and relay. These modules are connected 28 in series to form a 201.6 V 6.5 Ah battery (traction battery), also known as the energy storage system. The computer controlled charge controller and battery management computer systems keep this battery between 38% and 82% state of charge, with a tendency to keep the average state of charge around 60%. By shallow cycling the battery only a small portion of its net available energy storage capacity is available for use (approximately 400 Wh) by the hybrid drive system, but the shallow computer controlled cycling dramatically improves the cycle life, thermal management control, and net long term calendar life of the battery. Active cooling of this battery is achieved by a blower motor and air ducting, while passive thermal management was accomplished through the metal case design. Battery life cycle Overall fuel economy of the 2001 model was 40.6 miles per US gallon (5.79 L/100 km; 48.8 mpg‑imp) while the 2002 Prius with high mileage delivered 40.4 miles per US gallon (5.82 L/100 km; 48.5 mpg‑imp). The magazine concluded that the effectiveness of the battery has not degraded over the long run. The cost of replacing the first generation battery varies between US$2,200 and US$2,600 from a Toyota dealer, but low-use units from salvage yards are available for around US$500. One study indicates it may be worthwhile to rebuild batteries using good blades from defective used batteries. Air-conditioning (HVAC) The HVAC system uses an AC induction motor to drive a sealed-system scroll compressor, a design principle not usually used in automotive applications. Using a scroll compressor increases the efficiency of the system, while driving it with an AC induction motor makes the system more flexible, so the AC can run while the engine is off. Because the oil used with the refrigerant gas also flows in the area of the high-voltage motor-windings, the fluid must be electrically insulating to avoid transmitting electric current to exposed metal parts of the system. Therefore, Toyota specifies a POE oil (designated ND11) is required for repairs. The system cannot be serviced with equipment normally employed for regular cars, which typically use PAG oils, as the equipment would contaminate the ND11 oil with PAG oil. According to SAE J2843 the oil provided from maintenance equipment must contain less than 0.1% PAG when filling. One percent PAG oil may result in an electrical resistance drop by a factor of about 10. Lifetime energy usage In 2008, the British government and British media requested that Toyota release detailed figure for the energy use and carbon dioxide emissions resulting from the building and disposing of Prius. Toyota has not supplied the requested data to address statements that the lifetime energy of Prius (including the increased environmental cost of manufacture and disposal of nickel-metal hydride battery) is outweighed by lower lifetime fuel consumption. Toyota states that lifetime CO2 saving is 43 per cent. As of 2010, the UK Government Car Service has operated 100 Priuses, and list the Prius having the lowest CO2 emissions in its fleet. Electromagnetic fields The Prius uses electric motors in the hybrid propulsion systems, powered by high voltage battery in the rear of the car. There have been some public concern of whether the levels of electromagnetic field exposure within the cabin are higher than comparable cars and what health effects those fields may present. However, Toyota and several independent studies have indicated aside that from a brief spike when accelerating, the electromagnetic fields within the Prius are no different from those of a conventional car and do not exceed the ICNRP exposure guidelines. A 2013 study by the Mayo Clinic found that patients with implanted cardiac devices such as pacemakers and defibrillators can safely drive or ride in hybrids or plug-in electric cars without risk of electromagnetic interference (EMI). The research was conducted using implantable devices from the three major manufacturers and a 2012 Toyota Prius hybrid. The study used 30 participants with implanted devices, and measured electric and magnetic fields in six positions inside and outside the Prius, and each position was evaluated at different speeds. Quietness The Wall Street Journal reported in February 2007 on concerns that quiet cars like the Prius may pose a safety risk to those who rely on engine noise to sense the presence or location of moving vehicles. Blind pedestrians are a primary concern, and the National Federation of the Blind advocates audio emitters on hybrid vehicles, but it has been argued that increased risks may also affect sighted pedestrians or bicyclists who are accustomed to aural cues from vehicles. However, silent vehicles are already relatively common, and there is also a lack of aural cues from vehicles that have a conventional internal combustion engine where engine noise has been reduced by noise-absorbing materials in the engine bay and noise-canceling muffler systems. In July 2007, a spokesman for Toyota said the company is aware of the issue and is studying options. In 2010, Toyota released a device for the third-generation Prius meant to alert pedestrians of the proximity. Japan issued guidelines for such warning devices in January 2010 and US approved legislation in January 2011. Models equipped with automatically activated systems include all 2012 and later model year Prius family vehicles that have been introduced in the United States, including the standard Prius, the Prius v, the Prius c and the Toyota Prius Plug-in Hybrid. The warning sound is activated when the car is travelling at 24km/h and cannot be manually turned off. Marketing and culture In the UK, the Advertising Standards Authority, an independent body charged with policing the rules of the advertising industry, ruled that a television advert for the Toyota Prius should not be broadcast again in the same form, having breached rules concerning misleading advertising. The advertisement stated that the Prius "emits up to one tonne less CO2 per year", while on-screen text included "1 tonne of CO2 less than an equivalent family vehicle with a diesel engine. Average calculated on 20,000 km a year." Points of contention were the vehicles chosen for comparison, whether "'up to' one tonne less" adequately communicated that reductions could be lower, and whether the distance used was appropriate: 20,000 km per year is around a US car's average annual driving distance, while a UK car's is 13,440 km. Government and corporate incentives There have been a number of governments with incentives intended to encourage hybrid car sales. In some countries, including the US and Canada, some rebate incentives have been exhausted, while other countries such as the United Kingdom, Sweden, Belgium, and the Netherlands have various or alternative incentives to purchasing a hybrid vehicle. Several US companies offer employees incentives. Bank of America will reimburse US$3,000 on the purchase of new hybrid vehicles to full- and part-time associates working more than 20 hours per week. Google, software company Hyperion Solutions, and organic food and drink producer Clif Bar & Co offer employees a US$5,000 credit toward their purchase of certain hybrid vehicles including the Prius. Integrated Archive Systems, a Palo Alto IT company, offers a US$10,000 subsidy toward the purchase of hybrid vehicles to full-time employees employed more than one year.